Titus LATE MISSISSIPPIAN AMMONOID PALEONTOLOGY AND BIOSTRATIGRAPHY OF THE ANTLER FORELAND BASIN Utah Geological Survey Bulletin 131 OF THE AND BIOSTRATIGRAPHY AMMONOID PALEONTOLOGY MISSISSIPPIAN LATE Titus PALEONTOLOGY SERIES, VOLUME 2 LATE MISSISSIPPIAN (ARNSBERGIAN STAGE-E2 CHRONOZONE) AMMONOID PALEONTOLOGY AND BIOSTRATIGRAPHY OF THE ANTLER FORELAND BASIN, CALIFORNIA, NEVADA, UTAH by Alan L. Titus Photos by author Large photo: Calcareous concretion with abundant Eosyngastrioceras hesperium (Miller and Furnish) topotypes, the most common Arnsbergian ammonoid in the Antler foreland, Trough Springs Canyon, Nevada. Two small photos: Two views of Stenoglaphyrites intermedium n. sp. from the Sheep Range, Clark County, Nevada. BULLETIN 131 UTAH GEOLOGICAL SURVEY a division of 2000 DEPARTMENT OF NATURAL RESOURCES PALEONTOLOGY SERIES, VOLUME 2 LATE MISSISSIPPIAN (ARNSBERGIAN STAGE-E2 CHRONOZONE) AMMONOID PALEONTOLOGY AND BIOSTRATIGRAPHY OF THE ANTLER FORELAND BASIN, CALIFORNIA, NEVADA, UTAH by Alan L. Titus Utah Geological Survey Salt Lake City, Utah 84114-6100 currently: Paleontologist, Grand Staircase-Escalante National Monument Bureau of Land Management Kanab, UT 84741 ISBN 1-55791-649-7 BULLETIN 131 UTAH GEOLOGICAL SURVEY a division of 2000 DEPARTMENT OF NATURAL RESOURCES STATE OF UTAH Michael O. Leavitt, Governor DEPARTMENT OF NATURAL RESOURCES Kathleen Clarke, Executive Director UTAH GEOLOGICAL SURVEY Kimm M. Harty, Acting Director UGS Board Member Representing Craig Nelson (Chairman) ............................................................................................................... Civil Engineering D. Cary Smith .................................................................................................................................. Mineral Industry C. William Berge ............................................................................................................................ Mineral Industry E.H. Deedee O’Brien ........................................................................................................................ Public-at-Large Robert Robison ............................................................................................................................... Mineral Industry Charles Semborski .......................................................................................................................... Mineral Industry Richard R. Kennedy ................................................................................................. Economics-Business/Scientific David Terry, Director, Trust Lands Administration ..................................................................... Ex officio member UTAH GEOLOGICAL SURVEY The UTAH GEOLOGICAL SURVEY is organized into five geologic programs with Administration, Editorial, and Computer Resources providing necessary support to the programs. The ECONOMIC GEOLOGY PROGRAM undertakes studies to identify coal, geothermal, uranium, hydrocarbon, and industrial and metallic resources; initiates detailed studies of these resources including mining dis- trict and field studies; develops computerized resource data bases, to answer state, federal, and industry requests for information; and encourages the prudent development of Utah’s geologic resources. The APPLIED GEOLOGY PROGRAM responds to requests from local and state governmental entities for engineering-geologic investigations; and identifies, documents, and interprets Utah’s geologic haz- ards. The GEOLOGIC MAPPING PROGRAM maps the bedrock and surficial geology of the state at a regional scale by county and at a more detailed scale by quadrangle. The GEOLOGIC EXTENSION SERVICE answers inquiries from the public and provides infor- mation about Utah’s geology in a non-technical format. The ENVIRONMENTAL SCIENCES PROGRAM maintains and publishes records of Utah’s fossil resources, provides paleontological and archeological recovery services to state and local governments, conducts studies of environmental change to aid resource management, and evaluates the quantity and quality of Utah’s ground-water resources. The UGS Library is open to the public and contains many reference works on Utah geology and many unpublished documents on aspects of Utah geology by UGS staff and others. The UGS has several computer data bases with information on mineral and energy resources, geologic hazards, stratigraphic sections, and bibliographic references. Most files may be viewed by using the UGS Library. The UGS also manages a sample library which contains core, cuttings, and soil samples from mineral and petroleum drill holes and engineer- ing geology investigations. Samples may be viewed at the Sample Library or requested as a loan for outside study. The UGS publishes the results of its investigations in the form of maps, reports, and compilations of data that are accessible to the pub- lic. For information on UGS publications, contact the Natural Resources Map/Bookstore, 1594 W. North Temple, Salt Lake City, Utah 84116, (801) 537-3320 or 1-888-UTAH MAP. E-mail: [email protected] and visit our web site at http://www.ugs.state.ut.us. UGS Editorial Staff J. Stringfellow ....................................................................................................................................................Editor Vicky Clarke, Sharon Hamre...............................................................................................................Graphic Artists Patricia H. Speranza, James W. Parker, Lori Douglas..........................................................................Cartographers The Utah Department of Natural Resources receives federal aid and prohibits discrimination on the basis of race, color, sex, age, national origin, or disability. For information or complaints regarding discrimination, contact Executive Director, Utah Department of Natural Resources, 1594 West North Temple #3710, Box 145610, Salt Lake City, UT 84116-5610 or Equal Employment Opportunity Commission, 1801 L Street, NW, Washington DC 20507. Printed on recycled paper 2/00 FORWARD The science of paleontology has been vital to Utah and surrounding areas since the middle of the nineteenth century. Museums, universities, and government agencies around the world have amassed important collections of Utah fossils. Many of those collections have been pivotal to the overall geologic history of our planet, and more particularly Utah and the western states. More directly, these fossils have played important roles in our understanding of past life on land and in the sea. Scientific interest in Utah's fossils spans the realm of disciplines of natural history: stratigraphy, sedimentology, paleogeography, geochronology, evolution, historical geology, geochemistry, structural geology, taphonomy, biogeochemistry, taxon- omy, paleoecology, anatomy, functional anatomy, biomechanics, animal behavior, genetics and more. Public interest in paleontology in the past two decades has soared with the rise in popularity of dinosaurs, vast improvements in technology, blockbuster museum displays, and spectacular media productions. Nevertheless, the hard work of paleontology, conducted by paleontologists, con- tinues with ever-increasing intensity. Our need to disseminate technical information about Utah's fossil heritage continues to grow. The Utah Geological Survey Paleontology Series serves to partially satisfy that need. One of the most important functions of paleontology in the earth sciences is time correlation of rock strata using taxonomic analysis of fossils in different regions. Comparisons of certain species’ similarities between regions frequently allows for precise age dating and correlation of strata lim- ited only by the presence/absence of species and the speed at which they evolved. Between their first appearance in the early/middle Devonian, approximately 390 million years B.P., and their ultimate extinction at the K-T boundary, 65 million years B.P., no other single taxonomic group is as precise or as widely useful for time correlation of strata as the ammonoid cephalopods, an extinct distant relative of the modern chambered nautilus. This is especially true for the Carboniferous Era (360-285 million years B.P.), where ammonoid change was extremely rapid for reasons that are as yet not fully known, although global climate fluctuation is probably a key driving force. During Mississippian (Lower Carboniferous) time, a major island mountain range was thrust up in what is present-day central Nevada and east- ern California. To the east of the mountain range lay a long, narrow, deep ocean basin that paralleled the mountain chain. Into this basin, known as the Antler foreland basin, untold millions of tons of sand, gravel, and mud were shed from the west creating thick deposits of marine sandstone, shale, and conglomerate. On the eastern edge of this seaway conditions were more conducive to carbonate deposition and many thick limestone deposits formed. Strata throughout this basin contain an abundant ammonoid fossil record. This record is rivaled by no other fossil group for intercontinen- tal correlation, and yet is only just beginning to undergo intensive study. This paper is the very first of a series of comprehensive systematic studies on this extremely significant fauna which, when completed, will help to establish the Antler foreland in Utah, Nevada, and California as a global ref- erence for Carboniferous research. Herein the paleogeographic ranges of many taxa are extended from